Enabling remote quantum emission in 2D semiconductors via porous metallic networks

Here we report how two-dimensional crystal (2DC) overlayers influence the recrystallization of relatively thick metal films and the subsequent synergetic benefits this provides for coupling surface plasmon-polaritons (SPPs) to photon emission in 2D semiconductors. We show that annealing 2DC/Au films on SiO 2 results in a reverse epitaxial process where initially nanocrystalline Au films gain texture, crystallographically orient with the 2D crystal overlayer, and form an oriented porous metallic network (OPEN) structure in which the 2DC can suspend above or coat the inside of the metal pores. Both laser excitation and exciton recombination in the 2DC semiconductor launch propagating SPPs in the OPEN film. Energy in-/out- coupling occurs at metal pore sites, alleviating the need for dielectric spacers between the metal and 2DC layer. At low temperatures, single-photon emitters (SPEs) are present across an OPEN-WSe 2 film, and we demonstrate remote SPP-mediated excitation of SPEs at a distance of 17 μm. Here, the authors develop a reverse epitaxial process whereby a nanocrystalline Au film becomes highly textured and support a suspended 2D WSe 2 overlayer. Surface plasmon polaritons are launched in nanostructured Au by laser excitation and couple remotely to single photon emitters present in WSe 2 .